Method of extracting and recovering vanadium



Patented Jan. 6, 1925 UNITED STATESPATENT OFFICE.

JOSEPH L. DIXON, 0F ".JOLVERHAMPTON, ENGLANRASSIGNOR T0 BARTON R. SHOVER,

OF PITTSBURGH, IENNSYLVANIA.

METHOD EXTRACTING AND RECOVERING VANADIUM.

No Drawing.

To allevhom it may, concern:

Be it known that I, JOSEPH L. DIxoN, a subject of the King of England, residing at 88 Darlington Street, Wolverhampton, certain new and,

method of treating the ores from which the vanadium is extracted, 1n :1. cheap, ef-

fective and practical manner.

Most of such vanadium bearing iron ores are titaniferous,

thereof being as folloWs Per cent. F e 0 77 sio,- '10 Tio -12 V205 1 It a will be seen from the foregoing that ores of the above composition contain 56 per cent ofmeta-lli'c iron and 0.56 per cent of metallic vanadium, and that in treating such ores by a simple process of reduction the resulting product will contain not more than 1 per cent vanadium. However, if the novel reduction method of this ap lication be used, an alloy containing a muc greater percentage of vanadium will be produced. a i

On account of the high titanic acid content of ores similar to that ofthe composition given above, they can not be smelt- 7 ed economically in ablast furnace, but on the other hand such ores can readily be smelted and reduced to the metallic state in an electric furnace. As a result of electrically smeltingan ore of the above composition, together with suitable reducing and fluxing materials, there will be produced a pig iron'of'the following'compositiont t Per cent. Fe 94 Si 1.2 V 0.9

In addition there will be present small proportions of other elements, such as carbon, manganese, tltanlum, and the impurities I sulfur and a typlcal composition ferro silicon or solved in the pig iron. the process the slag containing the silicon as S O 1S separated from the metahand 95 i the first sta Application filed January 31, 1922. Serial No. 533,026.

not material to the present description.

According to my invention, pig iron of the above composition is submitted to oxidizing influences'in asuitable furnace so that there is obtained a slag containing a much higher proportion of vanadium oxide thanthe original ore. For example,.if such pig iron is blown in a Bessemer converter, and converted into soft steel, the. resulting slag will lowing composition- Per cent.

SiO 50 V 0 25 FeO 25 Such a slag can be converted into the ferro vanadlum, by using,

Well known alloy aluminum as a reducing agent.

p Alternatively the pig iron can be oxidized.

type of fun- I nace so as to obtaln a slag containing a in an open-hearth or similar valuable proportion of vanadium.

Iprefer, however, tocarry out the oxi' dation of the pig iron in two or more stages,

the objectof the first stage beingto oxidize the silicon, and of thelater stage, or stages to oxidize the vanadium. .The. silicon is vanadium, v the oxidapig iron can be stopped when the greater portion of the silicon is oxidized and when the greater oxidized than the more easily in the first stage,

and therefore, tion of the portion of the 'vana- (hum 1s still in the metallic state and disthe oxidation of the metal is th 11 continued,-

until the vanadiumyis oxidized and dis solved in a further slag; The object of,

conducting. the oxidation in two stages is to obtain the vanadium in a from silica.

As it is not possible toconductthe proc ess so that oxidation of thefsiliconiscom pleted before the oxidation of thevanadium charge of ore for reduction into pig iron and in this way the vanadium containedii'n phosphorus, but these are approximate the, fol- At thisstage in a slag as small, in bulk as possible and substantially free reduced to the slag is recovered bf bein i in the pig in. such large proportion as to render the slag unsuitable for smelting directly into ferro-vanadium. The vanadium in this slag can be recovered by mixing the slag with the materials. for. a subsequent smelting of the ore, or by using it in the earlier stages of oxidizin a subsequent charge ofpi iron.

The desira ility or undesirability continuin the oxidation into this I stage will depem largelyupon the qualities that are desired in the metallic bath. For example, if a soft steel is required it will be necessary to carry the oxidatlon into the third stage in order to remove the carbon dissolved in the metal. a i

The operations f oxidizing the metal accordin to the two or three stages which I have escribed can be carried on in the same or in separate furnaces. For exam le, the first stage of the oxidation, namely, t at for theremoval of silicon can be very con-' veniently performed in a Bessemer: converter. The secondsta of the oxidation, namely, that for the oxi ation of the larger proportion of the vanadium can be conveniently performed in an open hearthl furmace, "and more especially an open-hearth furnace having a basic lining, j c

Having regard, however, I to the economic i conditions under which the" metallurgical operations I have described arejconducted,

it is preferable that the operation of oxidizing the pig ironto be rformed entirely in an electric arc furnace of the tiltingtype 1 aIi with a basic lining. In a furnace of this kind the metallurgieal operations are most easily carried on and also the separa tion from thekmetal ofthevariousslags is.

tly facilitated. Accordingly, thehper- 5 ormance, in an electric furnace, of the'operations which have been outlined, will now be describedin greater detail, but it is to be understood that in doing so, the sec e of'my invention is not to be imited to tie exact 0 details disclosed, nor to the exclusive use of an electricfurnace. y I

Assumingthat an electricfurnace of one ton ca acity is to be used, then 2,000 ounds ofmo ten pi iron are poured into t e fur- 5 meta. The e ectrodes are lowered and the from the metal there will stillwill have approximately the 0 metal an current switched on and 50 pounds of lime are then thrown into the furnace, and as soon as this is heated to a slag forming temperature, hematite iron ore is added cautiously, which will rapidly oxidize the silicon, form ing a siliceous slag. When the fracture of a sample ofthe metal indicates that the metal contains ap roximately 0.2 per cent silicon (Si) the a dition of ore is stopped.

The furnace is then tilted towards the spout and the slag removed by rakingi This slag owing'composition--(GaO-50 per cent, SiO,-40 per cent, V O,---4 per cent, FeO-'-6 per cent),

and, as previously described, this slag 18. added to a subsequent charge of iron n ore" for reduction into pig iron.

After the remova of the siliceous slag about pounds of lime is thrown into .the the heating continued. Cautious additions of hematite ore are then made and are allowed time to react with themetal,.

so as to form an additional slag. When sufiicient ore has been addedand a suflicient time interval has elapsed, this slag is removed by raking. It is this slag that contains nearly the whole of the vanadium that was contained in the original pi iron. The composition of this slag will approximately CaO-55 per cent, V,O,25 per cent, Foo-11 r cent, SiO,-9 r cent. This slag is an sequently reduce into the well known alloy ferro-vanadium, by smelting in an electric furnace with ferro-silicon as a reducing agent.

' At'this stagethe metallic bath will contain about .02 per cent Si and .08 per cent cove lime are adde V, and by further oxidation a further re of vanadiumcan be made. To accomp ish this (purpose, thirty pounds of to the bath, and shortly afterward ore additions are made until the bath iscompletel oxidized. The resulting "slag "will have t e following a roximate F tiger cent, .V O,,-4 per cent. This slag is ad ed to a sub composition CaO-60 per cent,

sequent charge of ore for. reduction into pig iron and its vanadiumso recovered.

Alternatively it is'usedin pl'acefof or mixed with hematite ore for carryingon the preliminary oxidation of as'ubsequent charge of pig iron for the removal of silicon, m

which case the vanadium is recovered by the reducing actlon of the silicon, according to the equation--- 7 e c 5si+2v,o, .-5sio,+2v,[

The vanadium reduced from this slag is dis solved in the pig iron and subsequently obtained in the slag of greater concentration resulting from the second stage of the oxidation of the pig iron. i According to circumstances, it may be found more convenient notwto continue the oxidation into the third stage, but to cast the metal without further oxidation. Economic requirements may make it convenient to replace the carbon which has been oxidized during the oxidation of the silicon and vanadium by additions of coke or anthracite coal, and to replace the silicon by additions of ferro-silicon. In this Way a soft gray iron suitable for foundry purposes will be obtained.

I claim 1. The process of extracting vanadium from vanadium bearing iron ores, which consists in reducing the ores to metallic iron, oxidizing said iron so as to form a slag richer in vanadium oxide than the original ore, and subsequently reducing the slag to a metallic alloy containing vanadium.

2. The process of extracting vanadium from vanadium bearing iron ores, which consists in reducing the ore into iron, reducing the iron to a molten state, oxidizing the molten iron so as to obtain a slag richer in vanadium oxide than the original ore, and subsequently reducing the slag so as to obtain a metallic alloy of iron and vanadium with a greater proportion of. vanadium relative to iron than was present in the original ore.

3. The process of extracting vanadium from iron or steel, which consists in reducing the iron to a molten state, oxidizing the iron or steel so as to obtain a slag containing a greater proportion of vanadium relative to iron than was present in the original iron or steel, and subsequently reducing the slag into an alloy of iron and vanadium.

l. The process of extracting vanadium from iron containing vanadium and silicon, which consists in reducing the iron to a molten state, partially oxidizing the molten iron so as to oxidize the silicon and form a siliceous slag, separating said siliceous slag from the molten metal, and further oxidizing the remaining metal to oxidize the vana dium content thereof and form a slag containing a higher proportion of vanadium relative to iron than was present in the origi nal iron.

5. The process of extracting vanadium from iron containing vanadium and silicon, which consists in reducing the iron to a molten state, partially oxidizing the molten iron so as to oxidize most of the silicon and form a siliceous slag, separating said siliceous slag from the molten metal, and further oxidizing the remaining metal to oxidize the remaining silicon and vanadium and form a slag containing a higher proportion of vanadium relative to the iron and also the silicon than was present in the original iron.

6. The process of extracting vanadium from pig iron or steel which consists in partially oxidizing the pig iron. or steel, so as to obtain part of the vanadium in a slag relatively rich in vanadium oxide and relatively poor in iron oxide,.and subsequently recovering substantially the whole of the vanadium remaining in the pig iron or steel by further oxidizing the pig iron or steel, obtain- I ing a second relay richer in vanadium relative to iron than the original pig iron, but

ducing the mixture of slag and ore into iron.

8. The process of obtaining iron relatively rich in vanadium from iron' relatively poor in vanadium, which consists in first oxidizing a bath of the molten iron so as to obtain a slag richer in vanadium relative to iron than the original iron, and subse-- quently adding'the slag to a second bath of the molten iron.

9. The process of extracting vanadium from an alloy of iron and vanadium, which consists in partially oxidizing the alloy .so as to obtain part of the vanadium in a slag relatively rich in vanadium oxide and relatively poor in iron oxide, and subsequently recovering substantially the whole of the vanadium remaining in the alloy by further oxidizing the alloy, obtaining a second alloy richer inyanadium relative to iron than the original alloy, but poorer in yanadium relative to iron than the first slag.

10. The process of obtaining iron alloys relatively rich in vanadium from an ore relatively poor in vanadium, which consists in first reducing a charge of ore into a metallic alloy and then oxidizing the alloy so as to obtain a slag richer in vanadium relative to iron than the original ore, and subsequently mixing the slag with a further charge of ore and reducing the mixture of slag and ore into a metallic alloy.

11. The process of extractingvanadium from vanadium bearing ores, which consists of reducing the ores to metallic iron, reducing the metallic iron to a molten state, heating said iron to a slag forming temperature, adding sufi'icient hematite ore to oxidize the silicon content of the molten metal andform a siliceous slag, removing the siliceous slag, reheating said metal to a higher temperature, adding lime and sufiicient additional hematite ore to said reheated metal to form asecond slag containing approximately all of the vanadium content of said ore, and lastly removing said second slag from said molten lIOIl.

In testimony whereof I have hereunto set m hand.

y JOSEPH L. DIXON. 

